Question

A rectangular prism has a base of 18 cm by 15 cm and a diagonal of 25 cm. Identify its height. Round to the nearest tenth. HELP PLEASE! I don't understand this question!!

Answer 1

8.7 cm

Explanation:

You know the relationship between the diagonal of a rectangular prism and the sides as
`d^2 = x^2 + y^2 + z^2` where x, y and z are the three dimensions of the prism. from your data,
`25^2 =18^2 + 15^2 + z^2` or
`z^2 = 25^2 -18^2 - 15^2`. With some simple calculation you get
`z^2 = 625 - 324 - 225 = 76`, or
`z= 8.7178....`